Slack-rope stop for elevators



(No Model.)

W. E. NIOKER'SON.

SLAGK ROPE STOP FOR ELEVATORS.

-No. 404,014. 4 Patented May 28, 1889.

N. PETERS mmmm m. Washington. ac.

UNITED STATES PATENT OFFICE.

\VILLIAM E. NICKERSON, OF CAMBRIDGE, MASSACHUSETTS.

SLACK-ROPE STOP FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 404,014, dated May 28,1889. Application filed February 15, 1889. Serial No. 299,956. (Nomodel.)

To all whom it may concern.-

Be it known that 1, WILLIAM EMERY NICK- ERSON, of Cambridge, in thecounty of Middlesex and State of Massachusetts, have invented certainnew and useful Improvements in Slack-Rope Stops for Elevators, of whichthe following, taken in connection with the accompanying drawings, is aspecification.

The object of my invention is to apply a simple and reliable device tothe windingdrum of an elevator, so that in case the hoisting-rope fromany cause becomes slack an automatic device at once acts on the handropewheel and ships the driving-belt onto the loose pulley, and thus stopsthe further movement of the hoisting mechanism. This object I attain bythe mechanism shown in the accompanying drawings, in which- Figure 1 isa side elevation of the essential parts of the hoisting apparatus of anelevator, in connection with which I show one method of applying mydevice. Fig. 2 is a View, partly in elevation and partly in verticalsection, showing the more immediate parts to which my device relates.Fig. 8 shows details in elevation.

In the drawings I have shown my device as applied to an elevator inwhich the power is transmitted by means of belts, and the controllingmechanism consists of a beltshipping apparatus; but my invention willapply also to an elevator of which the hoisting mechanism is operated bysteam, air, or hydraulic pressure without the intervention of belts, inwhich case the working effect of my device will be transmitted to thecontrolling mechanism by such means as the case requires-by levers andValves, for instance. A, Figs. 1 and 2, represents the bed-plate or baseof an elevator hoisting-machine; A the winding-drum, and A its shaft.This drum is driven by means of a gear and worm, A B B being theworm-shaft, upon which the fast pulley B and the loose pulley O O aremounted. The belt-shipping and brake devices are of the ordinaryconstruction, and need not be especially referred to.

The hoisting-rope H passes through the shell of the winding-drum A at anacute angle with a tangent to the rim of the drum at that part, so thatthe rope, when slack, may be drawn in by the action of thespring-retractor S, and has a rope-end coupling-piece, H, firmly affixedto its end. The rope-end coupling-piece H is attached to the arm or hookL of a rocker-shaft, L, which is located within the winding-drum A andquite near the central shaft, as shown. On the rockershaft L, I place apawl, L said pawl being rigidly attached, so that any movement of theshaft L will cause a corresponding move ment of the pawl L The swingingend of the pawl L has a hook, L Fig. 3, which engages with the teeth onthe pinion K. The pinion K rotates independently of the shaft A of thewinding-drum and engages with the gear-wheel K, firmly fastened to theshaft K of the hand-rope wheel M, through which the belt-shippingmechanism is operated.

The arm L of the rocker-shaft L is connected to a spring-retractor, S,Figs. 1 and 3, which has a tendency to draw the arm in the direction ofthe arrow S, and will so draw it unless it is held back by thehoistingrope, when under strain, in its normal position, as shown in thedrawings. When the arm L is held by the hoisting-rope in its normalposition, it, acting through the rockershaft L, holds the hook L of thepawl L away from the teeth of the pinion K, and as the pinion K is freeon the shaftA the windin g-dru m can revolve in either direction withoutimparting its motion to the pinion K.

The operation of my device is as follows: If the hoisting-rope H, fromany cause, becomes slack while the drum is in motion and lowering thecarriage, (which happens when some obstruction checks the descent of thecarriage,) then it at once (being resilient) loosens on the drum andwill no longer withstand the tension of the spring-retractor S on thearm L. As a consequence the arm L will move in the direction of thearrow S, and will turn the rocker-shaft L sufliciently to cause the hookL of the pawl L Figs. 2 and 3, to engage with the teeth of the pinion Kand cause the pinion K to rotate with the drum A This rotation of thepinion K will cause the gear K, shaft K and hand-rope wheel M to rotatein such a direction as to throw, by means of the belt-shipper, thelowering-belt off from the fast pulley, and thus stop the hoistingapparatus from further operation. The object of thus stopping the drumis to prevent theslack rope from being entangled with the machinery, andthereby causing damage to the rope or other parts.

My device is self-setting, for as soon as the rope H has its normalstrain upon it the arm or hook L will be drawn over, so as to lift thepawl L out of contact with the teeth of the pinion K.

'From an examination of the above it will be understood that my deviceconsists in attaching the drum end of the hoisting-rope to a retractor,the reaction of which, when the rope becomes slack, will, by atransmitting device, act on the controlling mechanism of the elevatorand stop its further motion.

I claim- 1. In an elevator hoisting device, the combination of thewindin g drum A rigidly fixed to its shaft, and hoisting-rope H, with amovable rope-end coupling and retractor S, said end coupling having atransmitting mech anism adapted to operate the belt-shipping device,substantially as and for the purpose set forth.

2. In an elevator hoisting device, the combination of the winding-drum Arigidly fixed to its shaft, and hoisting-rope H, with thespringretractor S, and a transmitting mechanism adapted to set a pawl orother clutch device in working connection with the controlling device ofthe elevator, substan tially as and for the purpose set forth.

3. In an elevator hoisting device, the combination of the winding-drum Aand rope H with the arm or hook L, spring S, rocker-shaft L, pawl Lpinion K, gear K, shaft K and hand-rope wheel M, substantially as andfor the purpose set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 14th day of Feb ruary, A.D. 1889. v

WILLIAM E. NICKERSON.

WVitnesses:

FRANK G. PARKER, MATTHEW M. BLUNT.

